Method for sealing drying chambers and the like



1 April 7, 1931 I RQR. Jom-zs 1,799,375

METHOD FOR SEALING; DRYING' CHAMBERS AND THE LIKE Filed June 1927 2Sheets-Sheet .1

INVENTOR. .Roberl: domes.

ATTORNEY).

. R. R. Jones 1,799,375

METHOD FOR SEALING DRYING CHAMBERS AND THE LIKE I I April 7, 1931.

Fi1ed June 1, 1927 2 Sheets-Sheet 2 INVEZVTOR. Robe rt 12 Jones BY 824Patented Apr. 7, 1931 UNITED STATES PATENT OFFICE ROBERT IR. JONES, OFAKRON, OHIO, ASSIGNOR TO THE FIRESTONE TIRE AND RUBBER COMPANY, OFAKRON, OHIO, A CORPORATION OF OHIO METHOD FOR SEALING- DRYING CHAMBERSAND THE LIKE Application filed June 1, 1927. Serial No. 195,694.

This invention relates to methods of and pors, which mixture is thenwithdrawn for apparatus for sealing chambers used in drying, heating orotherwise treating web or strip material.

An object of the invention is to devise a method of sealing the inlet oroutlet of the drying or heating chamber through which the material isconducted for treatment in order to prevent leakage of air into orvapors out of the chamber at these points, said method comprisingmaintaining around the inlet or outlet a body of an inert gas at apressure greater than that within the 1 chamber and greater thanatmospheric. A further object is to provide an additional, mechanicalmeans for sealing the passages, and for confining the inert gas aboutthe inlet or outlet at a pressure greater than that within the chamber.

The foregoing and other objects are obtained by the device illustratedin the drawings and by the inethod and apparatus described below. It isto be understood that the invention is notlimited to the specific formthereof disclosed herein.

Of the accompanymg drawings: Figure 1 is a vertical section at theoutlet of a drying chamber illustrating a sealing device embodying theprinciples of the in-;

vention;

Figure 21's an enlarged sectional end detail of the {sealing device; and

Figure 3 is a side elevation thereof.

For purposes of. illustration, the seal embodying the invention will bedescribed in use on a known type of drying chamber for removing thevolatile and explosive solvent,

from a web of fabric which has been coated or saturated with a rubbersolution. In the drawings, the numeral 10 designates a chamber or tankin which is mounted a series of guide rollers 11 for carrying a web ofcoated fabric, indicated by a dotted line at 12, in a circuitous pathpast a number of heating coils 13, the fabric passing out of the tankthrough an elongated slot 1 1 and on to a plurality of suitable guiderolls and a reelin device. In order to carry off the vapors rom the itank, an inert gas is introduced at inlet 15 1 and circulated .past thefabric, forming a non-explosive; mixture with the solvent varecovery ofthe solvent and inert gas. The slot 14 is closed by a pair of abuttingfelt pads 16, between which the fabric 12 is adapted to pass, the padsbein su orted b lates 17 attached to the floo? of t he tank This closurealone, however, is incapable of preventing leakage of vapors from thetank to the atmosphere or leakage of air into the tank to form anexplosive mixture. An elongated box 18 is accordingly afiixed to thetank about slot 14, and an additional pair of abuttingthe chamber at apressure greater than that within the tank, whereby if any leakage pastpads 16 occurs, it will be only the inert gas flowing from chamber 22into the tank. It is preferable. also to maintain the pressure inchamber 22 at a pressure higher than atmospheric to prevent theadmission of air into chamber 22 past closure pads or wipers 19, so thatleakage at this point would merely consist in the escape of the inertgas into the atmosphere. The inert gas is introduced into the chamberthrough one or more ports 23 therein from a supply pipe 24, and itspressure as well as the tank pressure is indicated on suitablemanometers or gauges (not shown). The lower portion of box 18 hasattached thereto a pair of hinged cover plates 25 for forming a finalpartial closure for the fabric passageway and also serving to protectthe wiper pads.

It will be understood that the sealing apparatus is also adapted for useat the inlet end of the tank, and that' modifications may be made in thestructures herein disclosed the appended claims.

What is claimed is:

1. The method of preventing leakage of vapors at the inlet or outletpassageways of drying apparatus for continuous strip material, whichcomprises maintaining a body of inert gas about said passageway at apressure greater than that of the vapors within the apparatus'andgreater than atmospheric pressure. 1 v

2. The method of preventing intermingling of air and solvent vapors atthe inlet or outlet passageways of apparatus for drying coated stripmaterial, which comprises providing a double seal at the passageway, andsupplying an inert gas to said seal above atmospheric pressure causingleakage of a'portion of said gas into said apparatus and into theatmosphere from the seal.

ROBERT R. JONES.

